VFD selection and harmonics: what to get right before the drive arrives
Sizing, bypass, braking, cable, and the harmonic distortion that variable-frequency drives push back onto your plant power.
Encoder
Position/speed feedback device.
Sensor reporting shaft position: incremental (pulses from a datum, needs homing) or absolute (true position after power loss). Resolution, output type, and noise immunity drive selection.
See also: Motion control · VFD
Use the concept: Automation ROI & payback calculator · Motor running current calculator
In depth
Automation ROI and payback: a business case operations can verify
Separate installed cost, cash savings, released capacity and recurring expenses, then test a conservative scenario before approving automation.
Motor kW, current, efficiency and power factor: keep the quantities straight
A three-phase example distinguishes shaft output, real input power, apparent power and running current, with the limits of a simple estimate.